Summer is the time for sun, sand and surf… but it’s also a critical time for skin protection.

Melanoma, the most dangerous type of skin cancer, has a high mortality rate if not caught early. If detected while still localized to one area of the skin, melanoma has a five-year survival rate of 65%. If diagnosed after metastatic disease has occurred, the five-year survival rate drops to just 16%. This year alone, more than 68,000 people will be diagnosed with melanoma and over 8,500 are expected to die.

The link between sun exposure and melanoma is well established. And you don’t have to live at the beach or lake to be at risk. A recent study in the Journal of Investigative Dermatology found that white women who vacation in warm-weather countries have 74% more moles than those who never vacationed in tropical climes. (A large number of moles is a risk factor for melanoma.) The association was greatest among women between the ages of 18 and 29.

One new study from M.D. Anderson Cancer Center shows promise in the fight against advanced melanoma. The clinical trial involved 185 people with metastatic melanoma. Half received the immunotherapy drug Interleukin-2 (Il-2) and the other half received a vaccine plus Il-2. The vaccine works by stimulating so-called “T” cells known for controlling immune responses. These T cells recognize the tumor cells as foreign and secrete enzymes that poke holes in the tumor cell’s membrane leading to disintegration.

Unlike vaccines for most diseases (mumps, measles, polio, etc.), which are meant to prevent the onset of illness, the melanoma vaccine is meant to facilitate treatment of a disease the body is battling. By stimulating the immune system to attack tumor cells, the vaccine calls upon the body’s own defenses to stop the tumor in its tracks.

Those who received the vaccine plus Il-2 had a significant response rate to the treatment compared to the Il-2 treatment alone. The vaccine group also nearly doubled progression-free survival rates. Overall, survival rates also improved.

Unfortunately, it may be a few years before such therapy is generally available. First, administration of Il-2 is tricky and requires specialized care for possible complications. Second, the existing vaccine can only be given to about half of those with melanoma because of the need to match the patient’s tissue type (referred to as HLA). So researchers need to figure out how to modify the vaccine’s protein structure to make more patients eligible.

For now, prevention is still the best cure, especially for those fair-skinned women in their late teens and 20s who like to maximize sun exposure during the summer. Be sure to load on a broad spectrum sunscreen; cover up or stay in the shade as much as possible; wear a broad-brimmed hat; and use sunglasses that block UV rays.